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Finding the Fourth Proportional to 780.34, 1,169.82 and 415.38

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Solution

The fourth proportional to 780.34, 1,169.82 and 415.38 is: 622.70

Step by Step Solution

  1. Step 1: Write the proportion equation
    780.34 : 1,169.82 = 415.38 : x
  2. Step 2: Convert to fraction form
    780.34/1,169.82 = 415.38/x
  3. Step 3: Cross multiply
    780.34x = 1,169.82 × 415.38
  4. Step 4: Simplify right side
    780.34x = 485,919.83
  5. Step 5: Solve for x
    x = 485,919.83/780.34
  6. Step 6: Final answer
    x = 622.70

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Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.